Building stairs in the garden - DIY, professional, costs?

We have been raging and raging in the garden over the past few days. The previous owners of the house left us a hill in the garden, planted quite closely with shrubs and so on, which looked very nice, but we don't have the time and patience for it, and it was all way too overgrown for us. It stole too much light.

So the garden has a lawn area, and then there is a hill that leads up to a field at the top. It was apparently piled up like that back then. We have cleared quite a bit now, we want to replant this hill somehow, but above all we want a staircase up the hill. You could wonderfully put a garden bench or a sun lounger there. We have various pictures in mind, looked at a lot online, but don't know if it's even remotely realistic to want to build such a staircase ourselves. Probably not? But whom do you commission for something like that? Tilers, gardeners, bricklayers? And what costs would you roughly expect?

This is what it currently looks like:

Depending on how "perfect" you want it, there are simple staircase constructions. For example: two thick boards as stringers, the same thickness as risers. Stabilize with driven iron rods, gravel the treads. Lasts many years even if wood does not like to be in the ground and is built quickly. With wooden planks it is even more durable.